add pickDeep utility function to pick nested properties from objects

common/script/libs/pickDeep.js

@@ -0,0 +1,13 @@
+// An utility to pick deep properties from an object.
+// Works like _.pick but supports nested props (ie pickDeep(obj, ['deep.property']))
+
+import _ from 'lodash';
+
+module.exports = function pickDeep (obj, properties) {
+  if (!_.isArray(properties)) throw new Error('"properties" must be an array');
+
+  let result = {};
+  _.each(properties, (prop) => _.set(result, prop, _.get(obj, prop)));
+
+  return result;
+};

common/script/ops/buyMysterySet.js

@@ -2,6 +2,7 @@ import i18n from '../i18n';
 import content from '../content/index';
 import _ from 'lodash';
 import splitWhitespace from '../libs/splitWhitespace';
+import pickDeep from '../libs/pickDeep';
 import {
   BadRequest,
   NotAuthorized,
@@ -43,7 +44,7 @@ module.exports = function buyMysterySet (user, req = {}, analytics) {
   user.purchased.plan.consecutive.trinkets--;
 
   return {
-    data: _.pick(user, splitWhitespace('items purchased.plan.consecutive')),
+    data: pickDeep(user, splitWhitespace('items purchased.plan.consecutive')), // TODO this is broken, _.pick doesn't support nested keys
     message: i18n.t('hourglassPurchaseSet', req.language),
   };
 };

common/script/ops/hourglassPurchase.js

@@ -2,6 +2,7 @@ import content from '../content/index';
 import i18n from '../i18n';
 import _ from 'lodash';
 import splitWhitespace from '../libs/splitWhitespace';
+import pickDeep from '../libs/pickDeep';
 
 module.exports = function(user, req, cb, analytics) {
   var analyticsData, key, ref, type;
@@ -50,5 +51,5 @@ module.exports = function(user, req, cb, analytics) {
   return typeof cb === "function" ? cb({
     code: 200,
     message: i18n.t('hourglassPurchase', req.language)
-  }, _.pick(user, splitWhitespace('items purchased.plan.consecutive'))) : void 0;
+  }, pickDeep(user, splitWhitespace('items purchased.plan.consecutive'))) : void 0;
 };

test/common/libs/pickDeep.js

@@ -0,0 +1,34 @@
+import pickDeep from '../../../common/script/libs/pickDeep';
+
+describe('pickDeep', () => {
+  it('throws an error if "properties" is not an array', () => {
+    expect(pickDeep).to.throw(Error);
+  });
+
+  it('returns an object of properties taken from the input object', () => {
+    let obj = {
+      a: true,
+      b: [1, 2, 3],
+      c: {
+        nested: {
+          two: {
+            times: true,
+          },
+        },
+      },
+      d: false,
+    };
+
+    let res = pickDeep(obj, ['a', 'b[0]', 'c.nested.two.times']);
+    expect(res.a).to.be.true;
+    expect(res.b).to.eql([1]);
+    expect(res.c).to.eql({
+      nested: {
+        two: {
+          times: true,
+        },
+      },
+    });
+    expect(res).to.not.have.property('d');
+  });
+});